Crop take-up arrangements are used in agriculture in order to take up crop lying on a field which, as a rule, had previously been dried and deposited in a swath, and to conduct it to a harvesting machine in which it can be compressed into a bale (balers), if necessary after a cutting process, deposited for transportation (self-loading forage box), chopped (forage harvester), or threshed out (combine). Take-up arrangements of this kind typically include tines, extending transverse to the direction of operation, attached to tine carriers. The tine carriers are brought into movement when a retainer supporting them is brought into rotation. The tines extend outward into intervening spaces that remain between strippers fastened to the frame of the crop take-up arrangement, and move along these intervening spaces. The tine carriers can be controlled by curved or cam tracks as, for example, disclosed in U.S. Pat. No. 2,388,212, so that the angular position of the tine carriers varies during their rotation in order to take up the harvested crop as aggressively as possible and in order to be able to retract into the interior space of the strippers at the delivery point, or they are not controlled, that is, they are rigidly connected to the retainer as disclosed in EP 0 903 077 A.
After a jam in the flow of the crop it is desirable to reverse the take-up arrangement, that is, to drive it in a direction opposite to the normal direction of the take-up operation. However typical take-up arrangements cannot be reversed, since the tines would become entangled with the housing. DE 102005020463A proposes that a guide arrangement be provided in the rear region of the tines which guides the tines into the intervening spaces between the strippers upon a reversal of the take-up rotor. Here the choice of the angle of the tines at the delivery point of the harvested crop is problematic, during conveying that angle should be as large as possible, but it should be as small as possible during any reverse operation. Analogously, problems occur on occasion at the point of entry of the tines at the rear, lower end of the housing during any reverse operation, since at that location an orientation of the tines as close as possible to the vertical direction of the strippers is desirable. However, such an angle is not optimum during the harvesting operation.
DE 4425142C describes a conveyor drum with a shaft supported in bearings located eccentrically to the axis of the conveyor drum, several fingers are supported in bearings on the shaft and extend through associated openings in the conveyor drum. The drum is driven in rotation. Since the shaft is supported in bearings, free to rotate in a region of rotation, it moves between two end positions on the basis of the forces applied to the fingers. The result is that the crankshaft reaches its one end position upon a first direction of rotation of the drum, and the fingers project relatively far out of the housing and actively convey the harvested crop. If the drum is reversed, the crankshaft rotates into its other end position and the fingers actively convey the harvested crop along.